docs: def run_index_cmd(name, cmd):
      """Run command, show errors if the returncode is non-zero."""
      sys.stderr.write("Creating {} index...\n".format(name))
      # Create index
      p = sp.Popen(cmd, shell=True, stdout=sp.PIPE, stderr=sp.PIPE)
      stdout, stderr = p.communicate()
      if p.returncode != 0:
          sys.stderr.write("Index for {} failed\n".format(name))
          sys.stderr.write(stdout)
          sys.stderr.write(stderr)